Apparatus for slotting piston rings



Nov. 29, 1932. D. M; SOLENBERGER APPARATUS FOR SLOTTING PISTON RINGS Filed June 27. 1927 2 Sheets-Sheet l Nov. 29, 1932. D. M. SOLENBER-GER 9,

APPARATUS FOR SLOTTING PISTON RINGS Filed June 27, 192'? 2 s t -sh t 2 h avwcmi o'o Jeaw M. S0267? $5 a)" Patented Nov. 29, 1932 ourrso stares PATENT QFFICE DEAN Id. SOLENBERGER, 0F CLEVELAND, OHIO, ASSIGNOR TO THE SIMPLEX PISTON RING 00. OF All'ZERICl-l, 1130., OF CLEVELAND, OHIO, A CORPORATION OF OHIO APPARATUS FDR fiL-OTTING PISTON RINGS Application filed. .Tune 2?,

The invention relates to apparatus for slotting of piston rings of that type in which axial resiliency is imparted to the ring by parallel series of overlappingslots. Such rings are formed usually from cast iron and are originally of a width greater than that of the groove in which they have been in serted. The overlapping slots form flexible intermediate sections which permit of com pressing the ring axially to fit the ring groove but it is of the utmost importance that the resilient pressure against the sides of the groove should be accurately determined. It is equally important that the resilient axial pressure should be substantially equal in all portions of the ring and that no portion should be unduly weakened so as to endanger breakage.

To fulfill the conditions just described, it is necessary that the slotting of the rings should be very accurately performed. and that both the width and the length of the flexible sections should be accurately predetermined. l Vith this object in view the invention consists in the peculiar construction of means for holding and slotting the rings as hereinafter set forth.

In the drawings:

Figure l is a plan view showing the saw arbor and the ring holding jig with sections of the latter detached for the removal of the work.

Figure 2 is a side elevation parallel in section showing the saw in engagement with the work.

' Figure 3 is a longitudinal section the jig.

Fig. 4 is an elevation of one of the ring holders.

Figure 5 is a greatly enlarged cross section through a portion of the showing the ring held therein in position for slotting.

Figure 6 is a side elevation of one of the ring supports.

Figure 7 is a developed side elevation of the slotted ring. I a a As shown in Figure 7 the completed ring A is provided with parallel circumferential series of slots B, B, C, C which extend completely around the circumference leaving through 1927. Serial No. 201,836.

short uncut portions D between adjacent slots of each series. The ring is trans-split and the ends on opposite sides of the split preferably overlap as shown at E and E. These end portions must also be axially compressible which is preferably accomplished by extending one of the slots C across the split and the portions of the ring on opposite sidesthereof. The series of slots B, B, C, C are staggered with respect to each other which forms intermediate said slots a series of flexible bars F connected at one end by the uncut portion D to one side of the ring and at the opposite end by a similar uncut portion D to the opposite side of the ring. The bars F are resiliently flexible and the axial pressure developed against the sides of the ring groove is determined by the cross section of said bars in proportion to the length thereof. Thus it is important that both length and thickness of these bars should be accurately predetermined.

The slotting of the rings is accomplished by circular saws or mills which are necessarily of small gauge and consequently are very flexible. Thus using such saws without guiding means it would be impossible to slot the rings with any degree of accuracy or uniformity. Another diiiiculty is due to the small cross section of the ring and the flexibility of the portions adjacent to the slots. Still another difi'iculty is due to the fact that the ring is trans-split and therefore is radially flexible.

In View of the conditions just described I have devised a construction of jig which will hold the ring accurately positioned and against either axial or. radial displacement and which will also accurately guide the saws while operating upon the ring and in a predetermined plane thereof. This jig may be mounted upon any suitable construction of rotary indexing head (not shown) and on any suitable tool such as amilling machine for moving such head relative to the saw arbor during the performance of the work,

the specific construction being as follows:

7 In the drawings I have merely shown an arbor 1 on which the saws are mounted and in dotted lines the face plate 2 of the rotary f the ring. v members are spaced from eachoth'er by a distance equal to thegauge of the 'saw'plus -a slight addition for working clearance. The

bor are sleeves one or more -tIi-s1 '1 11embers 7 held from rotation by the'key o'r spline 8 and in cooperation with the head 3 forming the ring holders. The members 7 ar'ea'ccu'rately spaced from the head 3 and from each other by spacer rings 9 arranged adjacent to the center or hub portions thereof. 1O is a threaded outer end portionof the "arbor 5 and llisa winged nut'or oth'enme'a'ns engaging said threaded portion for clamping 'thewholeseri'es of m'embers'7and 3.

For holding the rings concentric withthe axisof the-jig and radially compressed to the working diameter each of the members?) and 7 is provided with a peripher'alflange 12 forming a seat for the outer cylindrical face These flanges 12011 adjacent outer fac'esofthe flanges are beveled ofi as showna t 13 leaving"only anarrow portion 14 forbearing against the saw. The saws 15 'aremoiinted upon the arbor 1 a'n'd'are suit- -ably""s paced to register'with the guide slots betweenfthe flanges 12 ofthe'succ'essive mem- "bets 3 and 7. Thus wh'en thejig i's -pr'op'erly indexed and is moved laterally 'withrespect itlie arbor the saws-1'5 will be gu'ided" into Leng'ag'ement with the rings "which *are be tween the successive menibers o'f the series.

T o 'peri'nit' of using the same sa'w giiides'for 1I\ $MK'."'1 1 I Iornnng tne parallel slots in different planes fof the ring the space betweenthe'members' 3 7' a's determined "by the spacers 9*is greater than the width ofthe' ring sothat the latter may be oifset' to' oneside'of s'uc'h space fas shown in Figure 5. The opposite side of the ring 13 positioned byja'spacer ring-l6 which also has an annular shoulder 17 for fitting against the inner cylindrical'fa'ce of the {pist'ofn ring and holding the same from displacement under the radial thrust of the saw.

permit of a slightradial contraction during [engagement of the shoulder 17 with the piston ringfand the radial depth of the spacer ring "is su'ificient to'give the desired degree'of rigidity in resisting radial thrust of the saws.

" 'With the constructionasdescribed; inopf'eiatio'n'anunslotted piston ring is first engag'edwith the flange 12 of themember 3,

the 5 ring being held outward against "such *flsn ge by its own radial resiliency. The spacenr'ing 16"1nay then be engaged with the "outer portion of the ring,the shoulder 17 extending inside of the ring to a point adj atain these slots parallel.

that the portion of the ring which is under displacement in any direction and without exerting pressure on them axially.

In order that the slots may be properly positioned with respect to the joint in the ring a stop is arranged for locating each joint in a predetermined position in the This stop may be formed bya member 19 preferably a piece of sheet metal placed in a saw kert in the flange 12. The stop projects far enough into the recess forthe ring so as to enter the narrow space between the ring ends thus holding said ring from circumferential displacement. The sawing or slotting is eflected by moving the arbortowards the saw arbor which causes each of the saws to enter the space between the guide faces 14 to cut completely through the ring. The length of the slot is determined by the diameter of the saw and the amount of radial inward movement. Also these two factors are preferably such that the ends of the slots will be substantially square or in other words, that the edge of the saw when completing the slot will extend substantially radially with respect to the ring. After the cutting of each slot the index head is adjusted to position the for the cutting of the next adjacent slot and so on until the whole series in the same plane is completed. The jig is then unclamped, the rings removed and the spacer rings 16 are placed on the op posite side of each piston ring. This when the is again assembled will position each of the'piston rings on the opposite side of the recess in which it is held which will'spa'ce the second series of slots from the plane of the first series. The amount of this spacing and the consequent width of the intermediate flexible bars of the rings is determined bythe ratio of the width of the ring to the width of the recess in which said ring and spa'cer'16 are located. Thus, in originally designing the jig any desired spacing of the slots may be arranged for. 1

It will be noted that in this sawing operation there is no reversal of the rings with respect to the saws but that the parallel slots are formed by a lateral shifting of the rings due to the placing of the'spacer ring first on one side and then on the other thereof. Thus if there is any tendency of the saw to lead. in one direction itwill take the same direction in cuttingeach of the parallel slots so as to main- It will also be noted the direct thrust of the saw will be supported against radially inward movement by the shoulder 17 on the spacer ring 16. This will prevent any displacement of the piston. ring during the sawing operation. During the sawing operation there is no axial pressure against the ring as the clamping pressure is taken by the spacer rings 9. This prevents any deformation of the ring after the cutting of the first series of slots and the fact that the saw pressure is all radial prevents lateral dis-- placement by the saw.

lVhat I claim as my invention is:

1. A jig for holding a piston ring comprising a pair of complementary axially adjustable members each having a cylindrical flange against which the outer cylindrical face or" the ring bears, said flanges together constituting a guide for a cutter, said jig and cutter being relatively movable for effecting engagement of the cutter with the ring and means for holding the ring from inward displacement under the thrust of the cutter.

2. A jig for holding a piston ring comprising a pair oi complementary axially adjustable members each having a cylindrical flange against Which the outer cylindrical face of the ring bears, said flanges together constituting a guide for a cutter, said jig and cutter being relatively movable for effecting engagement of the cutter with the ring, means for holding the ring within said flanges in a plurality of laterally ofl'set positions with respect to the plane of the cutter and for also holding the ring from inward displacement under the thrust of the cutter in each of said positions.

3. A jig for holding a piston ring comprising a pair of complementary members each having a cylindrical flange forming a bearing for the outer cylindrical surface of the piston ring, means for holding said members spaced and forming a recess beneath said flanges of greater width than the width a j of the ring and with the flanges spaced from each other to form a guide for a cutter and a spacer ring complementary to said piston ring to fill the space between said members and to hold said ring laterally oflset with respect to the cutter guide, said jig'and cutter being relatively movable for effecting engagement of the cutter with the ring.

4. Ajig for holding a piston ring comprising a pair. of complementary members each having a cylindrical flange forming a bearing for the outer cylindrical surface of the piston ring, means for holding said members spaced and forming a recess beneath said flanges of greater width than the width of the ring and with the flanges spaced from each other to form a guide for a cutter, said jig and cutter being relatively movable for effecting engagement of the cutter with the ring and a spacer ring complementary to said piston ring to fill the space between said members and to hold said ring laterally ofi'- set with respect to the cutter guide, said spacer ring having a shouldered bearing for fitting within the piston ring and holding the same; from radial inward displacement under the thrust of the cutter.

5. A jig for holding a piston ring comprising a pair of complementary members each having a cylindrical flange forming a bearing for the outer cylindrical surface of the pistonring, means for holding said members spacedand forming a recess beneath said flanges of greater width than the width of the ring and with the flanges spaced from each other to form a guide for a cutter, said jig and cutter being relatively movable for effecting engagement of the cutter with the ring and a spacer ring complementary to said piston ring and adapted to be alternately placed on and engaged with opposite sides thereof to fill the space between said members and to hold the ring oflset to one side or the other with respect to the plane of the cutter, said spacer ring having a shoulder for fitting within the piston ring and holding the same against the radial inward thrust of the cutter. 1

6. A jig for holding a piston ring comprising a pair of complementary members each having a cylindrical flange forming a bearing for the outer cylindrical surface of the piston ring, means for holding said members spaced and forming a recess beneath said flanges of greater width than the width of the ring and with the flanges spaced from each other toform a guide for a cutter, said jig and cutter being relatively movable for effecting engagement of the cutter with the ring and a spacer ring complementary to said piston ring and adapted to be alternately placed on and engagedwith opposite sides thereof to flll the spacebetween said members, said ring having a shoulder for fitting within said piston ring to hold the same from radial inward displacement under the thrust of the cutter and said spacer ring he ing-split to permit of a slight radial contraction during the engagement with the piston ring.

'7. A jig for holding a piston ring comprising a pair of complementary axially adjustable members each having :a cylindrical flange against which the outer cylindrical face ofthe ring bears, said flanges together constituting a guide for a cutter, said and cutterbeing relatively movable for effecting engagement of the cutter with the ring and means for holding the ring from radial inward displacement under the thrust of the cutter, and a stop engaging the trans-split in the ring for holding the same from circumferential displacement in said jig.

8. A jig for holding a piston ring compris,

ing a pairof complementary members each having a cylindrical flange for bearing against the outer face of the piston ring and together constituting a guide for a cutter, said jig and cutter being relatively movable for effecting engagement of the cutter with the ring, and means for holding said ring from inward displacement under the radial thrust of said cutter. 7

9. A jig for holding a series of piston rings adapted to be engaged by a series of cutters,

said jig comprising a member having a cylindrical flange for fitting against the outer face of the piston ring, the outer edge of said flange forming a guide for one of said cutters, a member having a complementary oppositely arranged flange, one or more intermediate members provided with double opositelv arran ed flan es s acers between .1 D I 7 M the several members for holding the cutter guiding faces of adjacent flanges spaced from each other to provide running clearance for the cutters and also forming recesses beneath said flanges of greater width than the width of the piston rings, spacer rings complementary to said piston rings and adapted to be alternatively placed on and engaged with the opposite sides thereof to fill the space of said recesses and to offset the piston rings on one side or the other of the plane of the cutter, said spacer ring having a shoulder for fitting within the piston ring and for holding the latter from radial inward movement under the thrust of the cutter and means for clamping all of said members in fixed relation and so as to register the respective cutter guides with the corresponding cutters.

10. A jig for supporting a piston ring comprising complementary members, each having a lateral annular extension fitting against the outer cylindrical face of the ring, said extensions having their outer edges arranged in opposed spaced relation and together constituting a guide for a tool to be passed therebetween.

7 11. A ig for supporting a piston ring comprising complementary members, each having a laterally extending annular flange bearing against the outer cylindrical face of the ring, said flanges having their outer edges arranged in opposed spaced relation and together constituting a guide for a tool to be passed therebetween.

12 A jig forsupporting a piston ring comprising complementary members, each having a laterally extending annular flange bearing against the outer cylindrical face of the ring, said flanges having their outer edges arranged in opposed spaced relation and together constituting a guide forv a tool to be I passed therebetween, said jig and tool being relatively movable for efiecting engagement of the tool with the ring, and means forpreventing inward displacement of the ring under the thrust of the tool.

In testimony whereof I aflix my signature.

' DEAN SOLENBERGER. 

